Electromagnet and relay



May 29, 1945. H. K, KOUYOUMJIAN ELECTROMAGNET AND RELAY Filed June 18,1942 2 Sheets-Sheet l INVENTOR. r/wmamwy/K/foamwvw4fi w Arr-024 5) May29, 1945.

H. KOUYOUMJIAN ELECTROMAGNET AND RELAY Filed June 18, 1942 2Sheets-Sheet 2" 5 B Y w M w Patented May 29, 1945 7 ELECTROMAGNET ANDRELAY Haroutium K. Kouyoumjian, Wakefield, R. L, as-

signor to Ward Leonard Electric Company, a

corporation of New York Application June 18, 1942, Serial No. 447,531

(Cl. l75341) 11 Claims.

This invention relates to an improved form of electromagnet applicableto various uses and to an improved form of relay for ope g or closin acontrol circuit or for actuating any element. The present embodimentshows the invention applied to a time delay relay responsive to anoverload controlling current.

The main object of the invention is to provide an electromagnet or relaywhich will not be objectionably. affected by shocks or jars in itscontrolling action and in general this is accomplished by imposing uponthe movable magnetic element a compound movement for securing thecontrolling action and which cannot be imposed upon the movable elementby shocks or jars. Another object is to provide a structure which iscompact in size and which may be conveniently manufactured andassembled. Another object is to provide a structure which will bedurable and dependable under long continued use. Another object is toavoid instantaneous response of the relay under extremely high values ofthe controlling current for the purpose of always providing at leastsome time interval in its action so that other devices of the controlsystem in which it may be used will have time to function before therelay attains its final attracted positiom Other objects and advantageswill be understood from the following description, and accompa yingdrawings which illustrate one embodiment of the invention.

Fig. l is a vertical section showing the invention applied to a timedelay relay; Fig. 2 is a section on the line 2-2 of Fig. 1; Fig. 3 is asection on the line 3--3 of Fig. 1; Fig. 4 is a section on the line 4-4of Fig. 1; Fig. 5 is a section on the line 5--5 of Fig. 1; Fig. 6 is asection on the line 6-4 of Fig. 1; Fig. 7 is a vertical section showingthe movable parts in their attracted position; Fig. 8 is a section onthe line 8-8 of Fig. '7; Fig. 9 is a section on the line 9-9 of Fig. 7;Fig. 10 is a section on theline Ill-l of Fig. 7; Fig. 11 is a section onthe line IIH of Fig. '7; and Fig. 12 is a vertical section showing theassembly of the magnetic element.

Referring to Fig. 1 the magnet is provided with upper and lower endplates I, la forming the main frame and are shown provided withrearwardly and inwardly projecting extensions for supporting the deviceon a panel. Between the end plates extends a tube 2 of magneticmaterial, such as iron or steel, and this may be formed from sheet metalwith a small space left between the meeting edges of the tube as shownin Fig. 4 for reducing the effects of induced eddy currents. This tubeforms a magnetic path between the end plates of the frame. A controlwinding or coil 3 is located within the tube and is shown wound upon atube 4 of insulating material, the coil being spaced from the end platesby intervening washers or disks of insulating material.

The upper magnetic end plate I is shown provided with inwardly extendingpoles 6, four being shown as indicated in Fig. 3, the spaces between thepoles being shown of circular form. The poles 6 are shown displaced fromvertical and horizontal lines by an angle of about 15 in a clockwisedirection. The lower end plate is similar in form to the upper endplateexcept that the poles to of the lower end plate, as shown in Fig.4, are displaced about 15 from vertical and horizontal lines in acounter-clockwise direction. It follows that the poles of the lower endplate are positioned angularly about 30 from those of the upper endplate in a counter-clockwise direction about the central axis of themagnet for the purpose later explained. Instead of making thisdisplacement 30, it may be made a lesser amount or a greater amount tosuit particular requirements.

Above the upper plate I is an insulating washer or disk I on which ismounted a contact head 8 of molded insulating material; and all theparts as thus far described are clamped firmly together by screw bolts8. The heads of the bolts are located in recesses at the four corners ofthe con tact head and extend downwardly outside of the winding and tube2 through the upper and lower end plates, lock washers and nuts beingapplied at the lower ends of the bolts for holding the parts firmlytogether.

IA tube IU of non-magnetic material, such as brass is located within theinsulating tube 4 and extends from a small distance above the upperplate I to a considerable distance below the plate la. The tube ishermetically sealed and at its lower end is a plug H which is brazed tothe tube and a plug l2 closes the upper end of the tube, being brazedthereto, and is provided with an upwardly extending central screwthreaded portion Ho. The tube is adapted to turn in opposite directionson its vertical axis through an angle of 30, sumcient clearance for thispurpose being provided between the tube and the poles of the end platesand the central insulating tube 4. The tube ID has no appreciablevertical movement being restrained from downward movement by a washer I3of insulating material fixed in position on the plug I2. This washerrests on a plurality of non-magnetic metal rings ll of phosphor bronze,or other suitable material, which in turn are supported by the poles ofthe upper end plate. There are three such rings shown each of 4 adifferent thickness from that of the others; and by removing one or moreof them the relay may be adjusted to have proper clearance forpermitting free rotation on these rings as bearings. The tube isrestrained from upward movement by a ring Illa of non-magnetic materialsoldered to the outside of the tube HI and positioned a 51118:: distancebelow the poles of the lower end P a c The magnetic plunger assemblyseparately shown in Fig. 12 is movable as a unit from its lowestposition shown in Fig. l to its uppermost position shown in Fig. '7. Itcomprises a main magnetic element l which in its lowest position isshown extending from about the middle of the winding 3 to a considerabledistance below the poles of the lower end plate. It is of generalstar-shaped form throughout its length being provided with four polesI50 which extend outwardly and are opposite the four poles of the lowerend plate or of the upper end plate according to the conditions ofoperation. The plunger i5 is provided with a central screw threadedopening and its lower end I5?) is of a reduced diameter. Below thisreduced portion is another magnetic element 16 of comparatively smallthickness, be ing of about the same thickness as the end plates or themagnet. The magnetic element It is or similar form to the magneticelement is having similar outwardly extending poles Ila.

The latter poles are displaced angularly about 30 in a counterclockwisedirection about the central axis of the magnet from the poles l5a of themain portion or the plunger. The magnetic element I6 is fixed inposition by the screw bolt ll which passes upwardly through the elementIt into the threaded opening of the element i5. After the parts aresecured together, a hole is threaded through the portion lib and thescrew for receiving a pin Ila for insuring the retention of the parts inplace.

The head of the screw I1 is provided with a flange ill: on which isseated loosely a ring l8 of non-magnetic material, such as brass.

The tube It) is filled with oil and then hermetically sealed. When theplunger is moved upwardly there is sufficient clearance between the rimof the ring l8 and interior surface of the tube in to permit slowpassage or the oil from above the ring to below the ring, giving aretarded movement of the plunger and thereby imposing a time-delayaction on the relay. When the plunger moves downwardly, the ring I! israised from its seat on the flange ill) by the action of the oil and byreason of the fact that the interior diameter of the ring is somewhatlarger than the diameter of the head or the screw and by reason of thering being chamfered on its upper interior portion, there is a freepassage or the oil from below the ring to above the rin This permits arapid downward movement of the plunger when the winding oi the relay isdeenergized.

The mid-portion oi the tube It! is depressed inwardly along a portion ofits length at the regions between the poles lid of the main element iiof the plunger. These inwardly depressed portions lb of the tube I! arewell shown in Fig. 5. Although afiording suiflcient clearance betweenthem and the plunger I! to allow free movement of the latter in avertical direction relatively to the tube ill, any turning movement ofthe plunger will be imparted to the tube ill by reason or the couplingformed by the depressions oi the tube between the poles of the plunger.

The contact head is provided with opposite recesses Ior reception of twocontact terminals i9v having clamping nuts and washers for connection toan external circuit controlled by the relay. The terminals are providedwith inwardly and outwardly extending portions 18a on the inner sides 0!which are riveted the two contact arms 20. The arms extend rearwardlyfrom the contact terminals at opposite sides of a central openin! andare then bent towards each other and carry the contacts 2| at theirinner ends. The contact arms are or phosphor bronze or similar materialIorming leaf springs for normally pressing the contacts 2| together. Onthe upwardly extending threaded portion l2a of the plug I2 is a brasstube 22 and outside of this is a separator 23 of molded insulation. Theoutside shape of this separator is square and above it and the tube 22is a disk 26 of insulating material and these parts are held in fixedposition on the threaded portion of the plug l2 by a nut Ho and lockwasher which are above the disk 24.

Under normal conditions when the winding of the relay is deenergized orcarrying insufllcient current to raise the plunger, the parts may beassumed to be in the position shown in Figs. 1 to 6. At this time thecontacts 2| are in engagement and the separator 23 is in the positionshown in Fig. 2 and not afiecting the contact arms. The poles of theupper magnetic element l5 are then opposite the poles 6a of the lowerend plate as shown in Fig. 4 and are oflset counter-clockwise about 30from the poles 8 of the upper end plate. At this time the position ofthe magnetic element I5 is under the full influence of the poles 6a orthe lower end plate and not affected materially as regards its axialposition by the poles of the upper end plate. Likewise at this time thepoles lid of the lower magnetic element are offset counter-clockwisefrom the poles 6a of the lower end plate as shown in Fig. 4.

When current is supplied to the winding 3 of the relay the path of themagnetic flux in the position of the parts shown in Figs. 1 to 6, isfrom the upper end plate through the tube 2 to the lower end plate andthence through its poles to the poles of the upper magnetic element IIand from the upper end of this element to the poles of the upper endplate. When the current through the relay winding exceeds apredetermined amount, such as by the passage or an overload currenttherethrough, the plunger assembly will be moved upwardly within thetube Ill, being retarded by the dashpot action of the oil and ring [8within the tube in the manner already described. During the upwardmovement the axial position of the parts remain as described withreference to Figs. 1 to 6 until the plunger approaches the upper limitof its movement. At that time the lower end of the magnetic element [5is leaving the influence of the poles in of the lower end plate and iscoming within the influence of the poles 8 of the upper end plate.Likewise the poles of the magnetic element I8 are coming within theinfluence oi the poles 6a of the lower end plate. In view of the factthat the poles [5a of the upper element are then displacedcounter-clockwise about 30 from the poles of the upper end plate andthat the poles 16a of the lower magnetic element are displaced about 30counter-clockwise from the poles of the lower magnetic element, thestrong magnetic influence between these poles results in the plungerassembly being turned about 30 in a clockwise direction at or near itsfully attracted position. The poles 15a are then opposite the poles ofthe upper magnetic end plate and the poles 18a are then opposite thepoles of the lower end plate. This turning movement imparted to theplunger assembly results in the tube ll being similarly turned owing tothe plunger II and the tube In being interlocked as regards rotarymovement in the manner previously described.

This fully attracted position of the plunger and the various relatedparts are shown in Figs. 7 to 11- The turnin of the tube and theseparator 23 results in opening the contacts H for resultant control ofthe external circuit, these parts then being in the position shown inFig, 8.

When the winding of the relay is deenergized, or its current reduced toa value insufficient to retain the plunger in its uppermost position,the latter will fall rapidly to the lower end of the tube and anycurrent in the relay winding will cause the poles l of the uppermagnetic element to assume a position opposite the poles of the lowerend plate. This results in turning the plunger assembly and the tube illin a counterclockwise direction bringing the parts back to the relativepositions shown in Figs. 1 to 6. But if the current in the relay windinis cut off entirely when the plunger is in its uppermost position, thepressure of the spring contact arms against the separator 23 may, ifdesired, impose the same counter-clockwise movement upon the tube illand the plunger so that the parts will then assume the position shown inFigs. 1 to 6 when the plunger is released from its uppermost position.This permits the closure of the contacts 2| in readiness to respond toany further controlling action upon the current in the relay windingexceeding a predetermined amount.

When the relay is utilized as an overload timedelay relay, the timedelay in the responsive action is prolonged when the overloads are ofmoderate value but the time delay in the response is much shorter whenthe overload is high or excessive. And unless the overload is continuedsufficiently long to result in the plunger assembly being raised to itsfully attracted position, no responsive action results. Furthermore, therelay, in the particular form shown, cannot respond immediately to anexcessively high overload because the upward travel of the plungerassembly requires some time interval in any event. Such action isdesirable when the control is utilized in a system wherein it is desiredto permit the action of other controlling devices before the overloadrelay can accomplish its control.

It is apparent that this improvement avoids the use of any elementwhichby its vertical movement alone, such as a latch rod or tripping plungerelement, may obtain the responsive controlling eilect. Consequently theeffects of shocks in a vertical direction, either up or down,

or vertical components of such shocks, cannotresult in improper orundesired control because the turning movement is also necessary forseouring a controlling response. Also any upward movement imparted tothe plunger assembly by shocks is retarded by the dashpot action and theeffects of the shock would, in practically all cases, be over before theplunger had reached or closely approached its upper limit of movement;and after the passing of the shocks, the plunger will fall rapidly toits lowest position. Even if the plunger attained its uppermost positionunder shock and even if a small current were passing in the relaywinding, no turning action of the parts and control of the externalcircuit would result because the design of the relay would be such thatthe passage of a considerable current in the relay winding would benecessary to turn the parts on their axis. If the plunger happened to bepart way up in the tube due to the presence of an overload current inthe relay winding, then the effect of a shock in raising the plungerwould be merely to reduce the time interval of the responsive action onthe relay; and such action would not be seriously objectionable. Asregards the effects of shocks in ahorizontal direction, the movable unitis symmetrical about its axis and mechanically balanced with the resultthat such shocks or horizontal components of such shocks, would have noeffect in affecting the response of the relay because any impact tendingto rotate the movable unit is counteracted by equal forces on oppositesides of the axis of the rotatable unit. It follows under theseconsiderations that this improvement is every effective in reducing theeffects of shocks and jars from any direction as regards improperlyaffecting its responsive action.

Although one embodiment of the invention has been described, variousmodifications and adaptations of the invention for particular purposesmay be made without departing from the scope thereof. Although thisdisclosure relates to the sepa time delay response of the relay, theresponsive action of the relay obviously could be caused to open acircuit or to move oneor more parts, according to the particularrequirements. In some cases the lower magnetic element of the plungerassembly may be omitted and only one magnetic element utilized where theforce for turning the plunger is sufliciently obtained by the use of onemagnetic element.

I claim:

1. An electromagnet comprising a magnet frame having two polar portionsone above the other and having their poles displaced angularly withreference to each other, a tube rotatable on its axis and supported bythe magnet frame, and a magnetic plunger vertically movable in said tubehaving polar projections opposite the poles of the lower of saidportions in its unattracted position and opposite the pole of the upperof said portions in its attracted position for imposing a turningmovement on said tube in passing to its attracted position.

2. An electromagnet comprising a magnet frame having two polar portionsone above the other and having their poles displaced angularlywithreference to each other, a tube rotatably supported by the magnet frame,and a magnetic plunger vertically movable in said tube and hav-- ing twomagnetic elements in alignment with each other with polar projectionsrelatively dis-' of the magnet frame for imposing a turning,

movement on said tube in passing to its attracted position, and meansactuated by said plunger within said tube for retarding the upwardmovement of the plunger and for permitting rapid downward movementthereof.

4. An electromagnet comprising a magnet frame having two polar portionsone above the other and having their pole displaced angularly withreference toeach other, a tube rotatably' aration of the contacts of thecontrol circuit by supported by the magnet frame, a magnetic plungervertically movable in said tube and having two magnetic elements inalignment with each other with polar projections relatively displacedcorrespondingly to the displacement of the poles of the magnet frame forimposing a turning movement on said tube in passing to its attractedposition, and means actuated by said plunger within said tube forretarding the upward movement of the plunger and for permitting rapiddownward movement thereof, said tube being hermetically sealed andcontaining a fluid medium.

5. An electromagnet comprising a magnet frame having two polar portionsone above the other and having their poles displaced angularly withreference to each other, a tube rotatable on its axis and supported bythe magnet frame, a magnetic plunger vertically movable in said tubehaving polar projections opposite the poles of the lower of saidportions in its unattracted position and opposite the poles of the upperof said portions in its attracted position for imposing a turningmovement on said tube in passing to its attracted position, and meansfor retarding the movement of said magnetic plunger in moving to itsattracted position.

6. An electromagnet comprising a magnet frame having two polar portionsone above the other and having their poles displaced angularly withreference to each other about the central axis of the magnet, a windingbetween said portions, an element supported by the frame and turnable onits axis, and a magnetic plunger movable within said winding andengaging said element and having polar projections opposite the poles ofthe lower of said portions in its unattracted position and during itsmovement toward it attracted position and opposite the poles of theupper of said portions in its attracted position for imposing a turningmovement on said element upon the magnetic plunger attaining itsattracted position. 4

'7. An electromagnet comprising a magnet frame having two polar portionsone above the other and having their poles displaced angularly withreference to each other about the central axis of the magnet, a windingbetween said portions, a magnetic element movable within said windingand having polar projections opposite the poles of the lower of saidportions and displaced from the poles of the upper of said portions whenin its unattracted position and during its movement toward its attractedposition, and opposite the poles of the upper of said portions anddisplaced from the poles of the lower of said portions when in itsattracted position for imposing first an upward movement and then arotary movement on said element in passing from its unattracted to itsattracted position, and means for supporting said element in itsunattracted position.

8. An electromagnet comprising a magnet frame having two polar portionsspaced from each other and having their poles displaced from alignmentrelatively to each other angularly about the central axis of the magnet,a winding between said portions, a magnetic plunger movable within saidwinding and having two magnetic elements in alignment with each otherwith polar projections relatively displaced corresponding to thedisplacement of the poles of the magnet frame, the polar projections ofone of said elements being opposite the poles of one of said polarportions and displaced from the poles of attracted position for theother of said portions when in the unattracted position of the plungerand during its movement toward its attracted position, and the polarprojections of the other of said elements being displaced from the polesof both of said portions when in the unattracted position and oppositethe poles of One of said portions when in the attracted position of theplunger for securing first a longitudinal movement of the plunger andthen a rotary movement of the plunger in passing from its unattracted toits attracted position, and means for supporting said plunger in itsunattracted position.

9. An electromagnet comprising a magnet P frame having a fixed poleextending therefrom,

a second fixed pole extending therefrom, said second pole being spacedfrom said first named pole and also displaced angularly from said firstnamed pole about the central axis of the magnet, a winding between saidpoles, a movable magnetic element within said winding and having a polarprojection opposite the pole of said second fixed pole and displacedfrom said first named fixed pole when in its unattracted position andduring its movement toward its attracted position, and opposite saidfirst named fixed pole and displaced from said second fixed pole when inits attracted position for imposing first a longitudinal movement andthen a rotary movement on said element in passing from its unattractedto its attracted position, and means for supporting said element in itsunattracted position.

10; An electromagnet comprising a magnet frame having a fixed poleextending therefrom, a second fixed pole extending therefrom, saidsecond pole being spaced from said first named pole and also .displacedangularly from said first named pole about the central axis of themagnet, a winding between said poles, a movable magnetic element withinsaid winding and having a polar projection opposite the pole of saidsecond fixed pole and displaced from said first named fixed pole when inits unattracted position and during its movement toward its attractedposition, and opposite said first named fixed pole and displaced fromsaid second fixed pole when in its imposing first a longitudinalmovement and then a rotary movement on said element in passing from itsunattracted to its attracted position, and means for retarding themovement of said magnetic element in moving to its attracted positionand for supporting said element in its unattracted position.

11. An electromagnet comprising a magnet frame having a polar portion, awinding, a magnetic plunger movable within said winding and having twomagnetic elements spaced from each other and having polar projectionsdisplaced angularly with reference to each other about the central axisof said element, the polar projections of one of said elements beingopposite the poles of said polar portion when in the unattractedposition of said plunger and during its movement toward its attractedposition, and the polar pfbjections of the other of said elements beingdisplaced from the poles of said portion when in the unattractedposition and opposite the poles of said portion when in the attractedposition of the plunger, for securing first a longitudinal movement ofthe plunger and then a rotary movement of the plunger in passing fromits unattracted position to its attracted position, and means forsupporting the plunger in its unattracted position.

HAROU'ITUM K. K9UYOUMJIAN.

